1992 240sx grinding problem

Any suggestions are greatly appreciated.............
When the wife backs her car up and applies the brakes she can hear a grinding noise seemingly coming from the rear wheels. The noise occurs only if she applies the brakes - reverse with no brakes and there is no noise.

There is no grinding or brake noise during normal forward driving when the brakes are applied.

I've taken off the wheels and visually inspected but didn't notice anything unusual (metal filings, etc). Thinking about tearing down the pad/caliper assembly - any ideas what to look for or possible fixes to try?

It sounds like your rear pads are shot causing the grinding noise when backing up. When you apply the brakes while going in reverse, the rear brakes do more work than they usually do. When you are driving and brake, the front brakes do most of the work as the car's weight shifts forward. It sounds like your pads are worn in the rear and that grinding is from the metalic backing grinding on the rotor. Replace your rear rotor and pads. Also if they are THAT worn, check the brake fluid...if you get air in there, its very dangerous...not to mention scary.

it could be something lodged in the brake system (pads/rotors) thats making it grind, but most likely that would cause a noise when driving forward. Probably worn pads like roll said.

I appreciate the replies - thanks. I'll r & r the rear brakes this weekend and see what I end up with.

I appreciate the replies - thanks. I'll r & r the rear brakes this weekend and see what I end up with.

check the fluids first though man. Dont wait until this weekend. If you get ANY amount of air in there from the fluid going low due to pads wearing out, you are putting yourself and your wife in BIG danger. Its happened to my dad and its scary. You press down on the brake pedal and absolutely nothing will happen.

Thanks for the suggestions - and here's an update: Checked the brake fluid and it's full. Removed the rear calipers, brake pads, and rotors. Couldn't find a damn thing that looked out of the ordinary. Pads are plenty thick and wearing evenly and rotors look to be in good shape. Didn't see anything that looked like it would make the rubbing/grinding noise when the brakes are applied in reverse.

The noise sounds awful and is pretty loud so I figured once I got things apart the problem would be obvious - what the hell am I missing?